The Dream

In Somnium (The Dream) a dreamer narrates a fantastical journey to the Moon, experienced by the young scholar Duracotus from Iceland. Guided by his mother and a demon he goes on a voyage to the lunar world. The experience is described from several perspectives, detailing the challenges of space travel and the strange sensations of weightlessness. The demon provides the Moons perspective observing Earth from afar and reflecting on the human condition from a cosmic pov. Blending the mystical with the scientific, it offers a narrative that explores both the possibilities of space travel and humanity's curiosity to reach beyond the stars.

Johannes Kepler born on December 27, 1571 in Weil der Stadt, Germany, was a mathematician, astronomer and astrologer whose work influenced our understanding of planetary motion. He grew up in a religious family with his father, a soldier often abandoning the family and his mother, a herbalist, who was later accused of witchcraft (pretty common at the time). Kepler suffered from smallpox as a child that left him with damaged vision.

He showed an exceptional talent for mathematics and attended the University of Tübingen, where his mentor Michael Mästlin introduced him to the heliocentric model — the theory proposed by Copernicus, that the Sun, not the Earth, sits at the center.

After that Kepler worked as a mathematics teacher in Graz for some years, where he also began with his own scientific research. With the rise of the Counter-Reformation, he and his wife as Protestant couple left Graz in 1600 and moved to Prague. There he began working as assistant for the Danish astronomer Tycho Brahe. After Brahe's death in 1601, Kepler inherited his extensive astronomical data and was appointed as Imperial Mathematician and Court Astronomer, a position he held for many years.

In 1609, Kepler published Astronomia Nova, his most famous work, in which he introduced the first two of his three laws of planetary motion. That same year, he began writing Somnium, combining fiction with his scientific ideas and surprisingly anticipated many modern understandings of gravity and the universe through speculation. Around the same time Galileo Galilei made groundbreaking discoveries with the revelation of the Moon's mountainous surface through a telescope. Though Kepler wrote Somnium in 1609, it was not published until after his death, when his son released it in 1634, complete with Kepler’s scientific footnotes.

His time in Prague was marked by the outbreak of the Thirty Years' War in 1618. The war led to uprisings and some of Kepler’s colleagues were executed. Meanwhile his mother who had been accused of witchcraft two years earlier, faced a trial that dragged on for years. Kepler did everything he could to defend her, and though he succeeded in her release, she later died due to the hardships of her imprisonment.

Kepler had to leave Prague and moved to Linz, where he continued to work as a teacher and mathematician. 1627 he found a new patron in Albrecht von Wallenstein in Ulm, who supported him in exchange for horoscopes and astrological guidance during the war. However, when Wallenstein lost power in 1630, Kepler traveled to Regensburg to claim his unpaid wages but was unsuccessful. Kepler fell ill with a fever soon after and died there at the age of 58.

Kepler’s work laid the foundation for modern astronomy and had a profound influence on later scientists like Isaac Newton. His three laws of planetary motion remain fundamental to our understanding of planet movement and space exploration today. Kepler considered himself a priest of the book of nature believing that studying the nature was a way to gain a deeper understanding of God’s creation. For him, science and religion were closely intertwined and he viewed his work as a form of worship.

Initially, I wanted to read A True Story by Lucian of Samosata (2nd century AD), which is often considered the first work of science fiction. After finishing Frankenstein — another early example of the genre — I wanted to dive deeper, exploring the blueprints of speculative fiction: books and ideas that emerged in times when such concepts didn’t exist.

Unable to find a suitable edition of A True Story, I stumbled upon Johannes Kepler’s Somnium — an overlooked gem from Germany, despite its groundbreaking nature. Matter fact, the work lay forgotten in an attic for a long time.

Kepler himself drew inspiration from Lucian’s celestial voyage, and in turn, his own work would influence later visions of space travel.

Somnium weaves together three narratives: that of the dreamer, the scholar, and the demon. Of these, the description of the journey to the Moon intrigued me the most. Unlike the mechanical transport methods imagined in later science fiction, Kepler takes a different approach. His protagonist is drugged and transported, experiencing the trip as a physical torture. Remarkably, Kepler’s depictions of gravity, lunar landscapes, and astronomical conditions mostly align in surprising ways with modern astrophysical principles.

»Then we expose our bodies to the open air and withdraw our hands. Our bodies curl up like spiders, and we move them almost solely by willpower, so that eventually the body's own mass drifts toward its intended destination. However, this momentum is too slow for us and therefore of little use. Thus, as mentioned, we accelerate it through our will. We rush ahead of our bodies to prevent them from suffering damage upon impact with the Moon.«

It is more than just an exercise in theoretical astronomy — it is deeply personal. The work reads not only as a scientific exploration but also as a direct challenge to the superstitions of his time. Kepler processes many personal aspects within it, like his old colleague Tycho Brahe. The story is enriched by extensive footnotes — both scientific elaborations and subtle countering to his critics — which Kepler added over the years.

Beyond its scientific and autobiographical dimensions, Somnium also engages with profound philosophical and theological ideas. In an era when only the righteous were believed to ascend to the heavens, Kepler’s protagonist reaches the Moon not through divine grace, but with the help of a demon, also suggesting that the pursuit of knowledge itself may be a form of ascension.

Reading Somnium today feels similar to engaging with early science fiction classics like Dune. But Kepler’s vision emerged at a time when such ideas were met with resistance, making it all the more radical in its context. It’s a short yet profound read, one that gains depth when explored alongside its historical and scientific context.

Immersing myself in Somnium — alongside Beatrix Langer’s Leitfaden für Mondreisende — was a pleasure. Keep in mind that it's very theoretical  and focuses mainly on science rather than fiction in the end (unfortunately imo). But you can pick out the exciting parts.